Method for fabricating semiconductor package and semiconductor package using the same

ABSTRACT

Provided are a method for fabricating a semiconductor package and a semiconductor package using the same, which can simplify a fabricating process of the semiconductor package by forming a lead frame on which a semiconductor die can be mounted without a separate grinding process, and can improve product reliability by preventing warpage from occurring during a grinding process. In one embodiment, the method for fabricating a semiconductor package includes forming a frame on a carrier, forming a first pattern layer on the frame, first encapsulating the frame and the first pattern layer using a first encapsulant, forming conductive vias electrically connected to the first pattern layer while passing through the first encapsulant, forming a second pattern layer electrically connected to the conductive vias on the first encapsulant, forming a first solder mask formed on the first encapsulant and exposing a portion of the second pattern layer to the outside, removing the frame by an etching process and etching a portion of the first pattern layer, and attaching a semiconductor die to the first pattern layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application makes reference to, claims priority to, andclaims the benefit of Korean Patent Application No. 10-2015-0174092,filed on Dec. 8, 2015, the contents of which are hereby incorporatedherein by reference, in their entirety.

FIELD

Certain embodiments of the disclosure relate to a method for fabricatinga semiconductor package and a semiconductor package using the same.

BACKGROUND

Recently, mobile communication terminals, such as cellular phones, smartphones, or the like, or small electronic devices, such as tablet PCs,MP3 players, digital cameras, or the like, tend to become smaller insize and lighter in weight. According to the tendency, semiconductorpackages constituting the small electronic devices are becoming smallerand lighter.

In particular, semiconductor packages capable of accommodating as manyI/O pads as possible while maintaining excellent thermal/electricalproperties of a lead frame and capable of improving pricecompetitiveness while maintaining fan-in and fan-out design flexibilityof a PCB laminate are required. According to such market requirements,routable molded lead frame (RtMLF) packages of a combination type, whichhave advantages of both of the lead frame and the PCB laminate, arebeing developed.

BRIEF SUMMARY

Embodiments of the present disclosure provide a method for fabricating asemiconductor package and a semiconductor package using the same, whichcan simplify a fabricating process of the semiconductor package and canimprove product reliability by preventing warpage from occurring duringa grinding process.

According to an aspect of the present disclosure, there is provided amethod for fabricating a semiconductor package, the method includingforming a frame on a carrier, forming a first pattern layer on theframe, first encapsulating the frame and the first pattern layer using afirst encapsulant, forming conductive vias electrically connected to thefirst pattern layer while passing through the first encapsulant, forminga second pattern layer electrically connected to the conductive vias onthe first encapsulant, forming a first solder mask formed on the firstencapsulant and exposing a portion of the second pattern layer to theoutside, removing the frame by an etching process and etching a portionof the first pattern layer, and attaching a semiconductor die to thefirst pattern layer.

According to another aspect of the present disclosure, there is provideda semiconductor package including a substrate including a firstencapsulant, a first pattern layer formed on the first encapsulant, asecond pattern layer formed under the first encapsulant, and conductivevias electrically connecting the first pattern layer to the secondpattern layer, a semiconductor die mounted on the substrate andelectrically connected to the first pattern layer, and a first soldermask formed under the substrate and exposing a portion of the secondpattern layer to the outside.

As described above, in the method for fabricating a semiconductorpackage, a lead frame on which a semiconductor die can be mounted may beformed without a separate grinding process by forming a first patternlayer and a first encapsulation on a frame, forming conductive viaspassing through the first encapsulation and forming a second patternlayer electrically connected to the conductive vias. Accordingly, thefabricating process can be simplified and warpage caused by a grindingprocess can be prevented, thereby improving the reliability of aproduct.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a flowchart illustrating a method for fabricating asemiconductor package according to an embodiment of the presentdisclosure;

FIGS. 2A to 2J are cross-sectional views illustrating the method forfabricating a semiconductor package illustrated in FIG. 1;

FIG. 3 is a flowchart illustrating a method for fabricating asemiconductor package according to another embodiment of the presentdisclosure; and

FIGS. 4A to 4C are cross-sectional views illustrating the method forfabricating a semiconductor package illustrated in FIG. 3.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments of thepresent disclosure, examples of which are illustrated in theaccompanying drawings. Various aspects of the present disclosure may beembodied in many different forms and should not be construed as beinglimited to the example embodiments set forth herein. Rather, theseexample embodiments of the disclosure are provided so that thisdisclosure will be thorough and complete and will convey various aspectsof the disclosure to those skilled in the art.

In the drawings, the thickness of layers and regions are exaggerated forclarity. Here, like reference numerals refer to like elementsthroughout. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items. In addition,it will also be understood that when an element A is referred to asbeing “connected to” an element B, the element A can be directlyconnected to the element B or an intervening element C may be presentand the element A and the element B are indirectly connected to eachother.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “comprise/include” and/or“comprising/including,” when used in this specification, specify thepresence of stated features, numbers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, numbers, steps, operations, elements,components, and/or groups thereof.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various members, elements, regions, layersand/or sections, these members, elements, regions, layers and/orsections should not be limited by these terms. These terms are only usedto distinguish one member, element, region, layer and/or section fromanother. Thus, for example, a first member, a first element, a firstregion, a first layer and/or a first section discussed below could betermed a second member, a second element, a second region, a secondlayer and/or a second section without departing from the teachings ofthe present disclosure.

Spatially relative terms, such as “below,” “beneath,” “lower,” “above,”“upper,” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “on” or “above” the otherelements or features. Thus, the exemplary term “below” can encompassboth an orientation of above and below.

FIG. 1 is a flowchart illustrating a method for fabricating asemiconductor package according to an embodiment of the presentdisclosure and FIGS. 2A to 2J are cross-sectional views illustrating themethod for fabricating a semiconductor package illustrated in FIG. 1.

Referring to FIG. 1, the method for fabricating a semiconductor packageaccording to an embodiment of the present disclosure includes forming aframe (S1), forming a first pattern layer (S2), first encapsulating(S3), forming conductive vias (S4), forming a second pattern layer (S5),forming a solder mask (S6), etching (S7) and attaching a semiconductordie (S8). Various steps of the method for fabricating a semiconductorpackage illustrated in FIG. 1 will now be described with reference toFIGS. 2A to 2J.

In the forming of the frame (S1), as illustrated in FIG. 2A, a frame 110is formed on a carrier 10. The frame 110 may be made of a metal, forexample, copper (Cu). In addition, the carrier 10 may be made of silicon(Si), glass, a metal or an equivalent thereof, but aspects of thepresent disclosure are not limited thereto. In addition, the frame 110may be formed by forming a seed layer on the carrier 10, followed byplating or being attached using an adhesive member, but aspects of thepresent disclosure are not limited thereto.

In the forming of the first pattern layer (S2), as illustrated in FIG.2B, a first pattern layer 120 is formed on the frame 110. The firstpattern layer 120 may be made of one selected from the group consistingof copper, aluminum, gold, silver, palladium and equivalents thereof,using electroless plating, electroplating and/or sputtering, but aspectsof the present disclosure are not limited thereto.

For example, the first pattern layer 120 may be made of the samematerial, e.g., copper (Cu), as the frame 110. In addition, patterningor routing of the first pattern layer 120 may be performed by aphotolithographic etching process using a photoresist, but aspects ofthe present disclosure are not limited thereto.

In the first encapsulating (S3), as illustrated in FIG. 2C, top portionsof the frame 110 and the first pattern layer 120 are encapsulated usinga first encapsulant 130. The first encapsulant 130 completelyencapsulates the frame 110 and the first pattern layer 120 to protectthe frame 110 and the first pattern layer 120 from external shocks andoxidation. The first encapsulant 130 may be made of one selected fromthe group consisting of a general thermally curable epoxy moldingcompound, a room-temperature curable glop top for dispensing, andequivalents thereof, but aspects of the present disclosure are notlimited thereto.

In the forming of the conductive vias (S4), as illustrated in FIG. 2D,conductive vias 140 are formed through the first encapsulant 130. Theconductive vias 140 are formed on the first pattern layer 120. That isto say, in the forming of the conductive vias (S4), the conductive vias140 passing through a top portion of the first pattern layer 120 areformed from a top portion of the first encapsulant 130. In detail, theconductive vias 140 may be formed by forming throughholes passingthrough the first encapsulant 130 by a fabricating process, such aslaser drilling, plating a thermally conductive metal having excellentelectrical and thermal conductivity, such as copper or aluminum,throughout inner walls of the throughholes, and filling or plating thethroughholes with a conductive material, such as a metal paste. Forexample, the conductive vias 140 may be made of the same material, e.g.,copper (Cu), as the frame 110 and the first pattern layer 120, butaspects of the present disclosure are not limited thereto.

In the forming of the second pattern layer (S5), as illustrated in FIG.2E, a second pattern layer 150 electrically connected to the conductivevias 140 is formed on the first encapsulant 130. The second patternlayer 150 is formed to upwardly extend from top portions of theconductive vias 140 to the top portion of the first encapsulant 130. Thesecond pattern layer 150 may be made of one selected from the groupconsisting of copper, aluminum, gold, silver, palladium and equivalentsthereof, using electroless plating, electroplating and/or sputtering,but aspects of the present disclosure are not limited thereto.

For example, the second pattern layer 150 may be made of the samematerial, e.g., copper (Cu), as the conductive vias 140. In addition,patterning or routing of the second pattern layer 150 may be performedby a photolithographic etching process using a photoresist, but aspectsof the present disclosure are not limited thereto. Moreover, the secondpattern layer 150 may be formed together with the conductive vias 140when the conductive vias 140 are formed in the throughholes in theforming of the conductive vias (S4).

In the forming of the solder mask (S6), as illustrated in FIG. 2F, aportion of the second pattern layer 150 is covered by a solder mask 160.In other words, the solder mask 160 may be formed on the firstencapsulant 130 and may expose the second pattern layer 150 by removinga portion of the solder mask 160. The solder mask 160 may be formed in aliquid type or a film type. In addition, the solder mask 160 may includealkyd resin, acrylate epoxy resin, methacrylate epoxy resin, and UVcurable resin, but aspects of the present disclosure are not limitedthereto.

In the etching (S7), the carrier 10 and the frame 110 are removed and aportion of the first pattern layer 120 is etched. First, as illustratedin FIG. 2G, in the etching (S7), the carrier 10 and the frame 110 areremoved by general dry etching or wet etching. Here, the carrier 10 maybe separated from the frame 110 by removing an adhesive memberinterposed between the frame 110 and the carrier 10 to then be removed.Accordingly, the first pattern layer 120 is exposed to the outside.Next, as illustrated in FIG. 2H, the portion of the first pattern layer120 is etched and a position of the underlying first pattern layer 120may be changed. Accordingly, a top surface of the etched first patternlayer 120′ may be positioned to be lower than that of the firstencapsulant 130.

Throughout the above-described fabricating process, a lead frame onwhich a semiconductor die can be mounted may be formed, and the leadframe is referred to as a routable molded lead frame (RtMLF) package. Inparticular, according to the present disclosure, the RtMLF package canbe fabricated without a separate grinding process, a warpage phenomenoncan be prevented from occurring during grinding.

In the attaching of the semiconductor die (S8), as illustrated in FIG.2I, the semiconductor die 170 is attached to the first pattern layer120′. That is to say, in the attaching of the semiconductor die (S8),bumps 171 of the semiconductor die 170 are electrically connected to thefirst pattern layer 120′ using a solder 172. The semiconductor die 170may be electrically connected to the first pattern layer 120′ using thesolder 172 without using the bumps 171. Here, the first pattern layer120′ and the second pattern layer 150 may be subjected to organicsolderability preservative (OSP) treatment to prevent the first patternlayer 120′ and the second pattern layer 150 from being oxidized. As anexample, the semiconductor die 170 may be electrically connected to thefirst pattern layer 120′ by a mass reflow process, a thermal compressionprocess or a laser bonding process. The solder 172 may be made of ametallic material, such as tin/lead (Pb/Sn) or leadless Sn, and anequivalent thereof, but aspects of the present disclosure are notlimited thereto.

In addition, the semiconductor die 170 may include, for example,electrical circuits, such as a digital signal process (DSP), amicroprocessor, a network processor, a power management process, anaudio processor, a radio frequency (RF) circuit, a wireless basebandsystem-on-chip (SoC) processor, a sensor, or an application specificintegrated circuit (ASIC).

In the attaching of the semiconductor die (S8), as illustrated in FIG.2J, the semiconductor die 170 is encapsulated using a second encapsulant180 and conductive bumps 190 are formed on the second pattern layer 150,thereby completing the semiconductor package 100 according to anembodiment of the present disclosure.

The second encapsulant 180 completely encapsulates the semiconductor die170 from a top portion of the first encapsulant 130 to protect thesemiconductor die 170 from external shocks and oxidation. The secondencapsulant 180 may be made of one selected from the group consisting ofa general thermally curable epoxy molding compound, a room-temperaturecurable glop top for dispensing, and equivalents thereof, but aspects ofthe present disclosure are not limited thereto.

In addition, the conductive bumps 190 may include, but are not limitedto, eutectic solders (e.g., Sn37Pb), high-lead solders (e.g., Sn95Pb)having a high melting point, lead-free solders (e.g., SnAg, SnCu, SnZn,SnZnBi, SnAgCu and SnAgBi), or equivalents thereto. Moreover, an underbump metal (UBM) may be formed on the second pattern layer 150 andconductive bumps 190 may be formed on the UBM.

As described above, in the method for fabricating a semiconductorpackage according to an embodiment of the present disclosure, the leadframe on which the semiconductor die 170 can be mounted may be formedwithout a separate grinding process by forming the first pattern layer120 and the first encapsulation 130 on the frame 110, forming theconductive vias 140 passing through the first encapsulation 130 andforming the second pattern layer 150 electrically connected to theconductive vias 140. Accordingly, the fabricating process can besimplified and warpage caused by a grinding process can be prevented,thereby improving the reliability of a product.

FIG. 3 is a flowchart illustrating a method for fabricating asemiconductor package according to another embodiment of the presentdisclosure and FIGS. 4A to 4C are cross-sectional views illustrating themethod for fabricating a semiconductor package illustrated in FIG. 3.

Referring to FIG. 3, the method for fabricating a semiconductor packageaccording to another embodiment of the present disclosure includesforming a frame (S11), forming a first pattern layer (S12), firstencapsulating (S13), forming conductive vias (S14), forming a secondpattern layer (S15), forming a first solder mask (S16), etching (S17),forming a second solder mask (S18) and attaching a semiconductor die(S19). Various steps of the method for fabricating a semiconductorpackage illustrated in FIG. 3 will now be described with reference toFIGS. 4A to 4C.

The steps of forming a frame (S11), forming a first pattern layer (S12),first encapsulating (S13), forming conductive vias (S14), forming asecond pattern layer (S15), forming a first solder mask (S16), andetching (S17) are the same as the steps of forming a frame (S1), forminga first pattern layer (S2), first encapsulating (S3), forming conductivevias (S4), forming a second pattern layer (S5), forming a solder mask(S6), etching (S7), as illustrated in FIGS. 2A to 2H, and detaileddescriptions thereof will not be given. In order to distinguish thesolder mask 160 covering a portion of the second pattern layer 150 inthe forming of the solder mask (S6) and a solder mask 260 covering aportion of a first pattern layer 120′ to be described below from eachother, the former is to be defined as a first solder mask and the latteris to be defined as a second solder mask. That is to say, the soldermask 160 formed in the forming of the solder mask (S6) may be referredas the first solder mask.

In the forming of the second solder mask (S18), as illustrated in FIG.4A, the portion of the first pattern layer 120′ is covered by the secondsolder mask 260. In other words, the second solder mask 260 may beformed on the first encapsulant 130 and may expose the first patternlayer 120′ by removing a portion of the second solder mask 260. Thesecond solder mask 260 may be formed in a liquid type or a film type. Inaddition, the second solder mask 260 may include alkyd resin, acrylateepoxy resin, methacrylate epoxy resin, and UV curable resin, but aspectsof the present disclosure are not limited thereto.

In the attaching of the semiconductor die (S19), as illustrated in FIG.4B, the semiconductor die 170 is attached to the first pattern layer120′. That is to say, in the attaching of the semiconductor die (S19),bumps 171 of the semiconductor die 170 are electrically connected to thefirst pattern layer 120′ using a solder 172. The semiconductor die 170may be electrically connected to the first pattern layer 120′ using thesolder 172 without using the bumps 171. Here, the first pattern layer120′ and the second pattern layer 150 may be subjected to organicsolderability preservative (OSP) treatment to prevent the first patternlayer 120′ and the second pattern layer 150 from being oxidized. As anexample, the semiconductor die 170 may be electrically connected to thefirst pattern layer 120′ by a mass reflow process, a thermal compressionprocess or a laser bonding process. The solder 172 may be made of ametallic material, such as tin/lead (Pb/Sn) or leadless Sn, and anequivalent thereof, but aspects of the present disclosure are notlimited thereto.

Additionally, in the attaching of the semiconductor die (S19), asillustrated in FIG. 4C, the semiconductor die 170 is encapsulated usinga second encapsulant 180 and conductive bumps 190 are formed on thesecond pattern layer 150, thereby completing the semiconductor package200 according to another embodiment of the present disclosure.

While the method for fabricating a semiconductor package and thesemiconductor package using the same according to various aspects of thepresent disclosure have been described with reference to certainsupporting embodiments, it will be understood by those skilled in theart that the present disclosure not be limited to the particularembodiments disclosed, but that the present disclosure will include allembodiments falling within the scope of the appended claims.

1-20. (canceled)
 21. An electronic device comprising: a substratecomprising: a first molded encapsulant having an upper encapsulant sideand a lower encapsulant side; a first conductive pattern at the upperencapsulant side and embedded in the upper encapsulant side of the firstmolded encapsulant; a second conductive pattern at the lower encapsulantside, where an upper side of the second conductive pattern is verticallylower than a lower side of the first conductive pattern; and aconductive path that extends through the first molded encapsulant andelectrically connects the first conductive pattern to the secondconductive pattern; an electronic component mounted on the substrate andelectrically connected to the first and second conductive patterns; anda second molded encapsulant over the first molded encapsulant and atleast laterally surrounding the electronic component.
 22. The electronicdevice of claim 21, wherein the second conductive pattern comprises aplated metal pattern comprising a flat lower side.
 23. The electronicdevice of claim 21, comprising an under bump metallization on a lowerside of the second conductive pattern.
 24. The electronic device ofclaim 21, wherein the conductive path extends vertically through thefirst molded encapsulant and comprises sloped sidewalls.
 25. Theelectronic device of claim 21, wherein the electronic componentcomprises an active side and a passive side, the active side facing thesubstrate.
 26. The electronic device of claim 21, wherein: theelectronic component is mounted on an upper side of the substrate; andthe electronic component comprises a contact that is soldered to thefirst conductive pattern.
 27. The electronic device of claim 21,comprising a vertical gap between the first and second conductivepatterns.
 28. The electronic device of claim 27, wherein a portion ofthe first molded encapsulant is directly vertically between the firstand second conductive patterns.
 29. An electronic device comprising: asubstrate comprising: a first molded encapsulant having an upperencapsulant side and a lower encapsulant side; a first conductivepattern at the upper encapsulant side and embedded in the upperencapsulant side; a second conductive pattern at the lower encapsulantside; and a conductive path that extends through the first moldedencapsulant and electrically connects the first conductive pattern tothe second conductive pattern; an electronic component mounted on anupper side of the substrate and electrically connected to the first andsecond conductive patterns; a conductive bump mounted on a lower side ofthe substrate; and a second molded encapsulant over the first moldedencapsulant and at least laterally surrounding the electronic component.30. The electronic device of claim 29, comprising an under bumpmetallization on the second conductive pattern and positioned directlyvertically between the conductive bump and the second conductivepattern.
 31. The electronic device of claim 29, wherein the conductivebump comprises a solder ball.
 32. The electronic device of claim 29,wherein the conductive bump is positioned directly vertically below theelectronic component.
 33. The electronic device of claim 29, wherein thefirst conductive pattern and the second conductive pattern each have arespective top and bottom horizontal side.
 34. The electronic device ofclaim 33, wherein the conductive path extends vertically between thebottom horizontal side of the first conductive pattern and the tophorizontal side of the second conductive pattern.
 35. The electronicdevice of claim 29, wherein a portion of the first molded encapsulant isdirectly vertically between the first and second conductive patterns.36. A method of manufacturing an electronic device, the methodcomprising: providing a substrate comprising: a first molded encapsulanthaving an upper encapsulant side and a lower encapsulant side; a firstconductive pattern at the upper encapsulant side and embedded in theupper encapsulant side; a second conductive pattern at the lowerencapsulant side; and a conductive path that extends through the firstmolded encapsulant and electrically connects the first conductivepattern to the second conductive pattern; mounting an electroniccomponent on the substrate and electrically connected to the first andsecond conductive patterns; and forming a second molded encapsulant overthe first molded encapsulant and at least laterally surrounding theelectronic component.
 37. The method of claim 36, wherein an upper sideof the second conductive pattern is vertically lower than a lower sideof the first conductive pattern.
 38. The method of claim 37, wherein aportion of the first molded encapsulant is directly vertically betweenthe upper side of the second conductive pattern and the lower side ofthe first conductive pattern.
 39. The method of claim 36, wherein saidmounting the electronic component comprises mounting the electroniccomponent on an upper side of the substrate, and further comprisingforming a conductive bump on a lower side of the substrate.
 40. Themethod of claim 39, further comprising forming an under bumpmetallization on the second conductive pattern and positioned directlyvertically between the conductive bump and the second conductivepattern.